Meet the latest way the superrich prove they're really, totally worried about the environment: $10 million electric superyachts

• Nico Rosberg took the Sunreef 80 Eco, a luxury electric yacht, for a spin.
• The yacht uses solar panels, wind, and hydropower for 10 hours of cruising per charge.
• Amenities include a self-playing piano, gym, and hotel-like cabin.

There has been a lot of chatter about the future of electric vehicles in recent months. As it turns out, the superrich have already moved on to electric yachts.

Sunreef Yachts recently unveiled their second-generation Sunreef 80 Eco. According to the company, it is "an eco-responsible luxury craft combining electric propulsion, superyacht living spaces, reliable sailing performance and the latest green technologies in the industry."

Former Formula One champion Nico Rosberg recently took one for a spin and gave an inside look at the luxury toy. It should be noted that since retiring from racing, Rosberg has become an "Elon Musk-worshiping" tech investor and eco-entrepreneur. So, this type of tech is important to him, even if it is out of reach for you and your friends.

The base price for the Sunreef 80 Eco is $9.5 million and goes up from there. 

The first thing you notice about the boat is the curved solar paneling, which is curved and built into the hull, roof, and even the sail mast. The panels cover over 160 square meters. 

The yacht also has a hydro propeller and wind generators to help recharge the battery and power the appliances, water toys, and tender (think your own personal tiny boat to get to shore), all of which are electric.

On one full battery charge, the yacht can do up to 10 hours of cruising at 8-10 knots of speed. The boat does have a diesel generator on board as backup and for longer trips. 

Another nice feature, from an eco perspective, is the lack of noise pollution. When the engine is running on battery, it is almost completely silent, as demonstrated here by Rosberg.

Of course, you can't have a luxury yacht without luxury amenities, and the Sunreef is loaded. 

Rosberg's version came with a self-playing piano and a pair of TechnoGym treadmills on the deck. The treadmills go for about $4,000 each.  

And then there is the cabin, which looks like it is straight out of a luxury hotel, with plenty of storage, a walk-in closet, and a walk-in shower.

You can watch the entire tour of the supertoy here.